Fort Hood Shooting Update — What We Know and What’s Being Investigated

More and more information keeps pouring out regarding the Wednesday-night shooting deaths at the Fort Hood Army base in Killeen, Texas. Here's a recap of what we've learned:

The alleged shooter, Specialist Ivan Lopez, 34, killed three and injured 16 others before being shot by a military police officer and then turning his weapon on himself. ABC is reporting that, just prior to his shooting rampage, he had been denied a leave-of-absence form, which may have been what initially enraged him, leading him to return armed.

Lopez had a clean record prior to Wednesday. He had "no outstanding bad marks for any kinds of major misbehaviors that we’re yet aware of," said Secretary of the Army John McHugh. Lopez had been seeing a military psychiatrist, who was treating him for anxiety and depression. He was also being evaluated for post-traumatic stress disorder following a four-month tour in Iraq in 2011, though he did not serve in combat while there.

Investigators are looking particularly closely at the issue of Lopez's mental health—since he apparently did not see any combat while in Iraq or during a 13-month stint on Egypt's Sinai Peninsula, the motivation behind the alleged shooting spree may have been "no more intelligible than the reasons behind school shootings or workplace killings."

"We have very strong evidence that he had a medical history that indicates an unstable psychiatric or psychological condition," said Lt. Gen. Mark Milley, commander of Fort Hood, on Thursday afternoon. "We believe that to be the fundamental underlying causal factor."